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Preliminary research on the ecology of Australia's first 'living fossil', the Wollemi Pine, suggests its growth habit may have enabled it to survive the occasional fire. But conservation agencies are still not relaxed, even though the current bushfire crisis is easing.

Fire crews are monitoring a large bushfire in the Wollemi National Park, 150 km northwest of Sydney, which is home to three stands of the Wollemi Pine (Wollemia nobilis)  a genus of tree which prior to 1994 was known only in fossils dating back to the age of the dinosaurs.

National park authorities are unwilling to confirm or deny whether the current fire is anywhere near the trees as this may give clues as to their whereabouts, which is a closely guarded secret designed to protect the trees from the destructive forces of intense human interest.

However according to John Benson of Sydney's Royal Botanic Gardens, recent evidence shows that previous fires have gone through at least two of the three sites where the Wollemi is growing.

"Charred trunks accompanied by new shoots coming from underground tubers have been found," he said.

"This together with growth rings on dead Wollemi Pines suggest that it has been able to come back after fires by coppicing," said Benson, who is investigating the ecology of the Wollemi Pine as part of its recovery plan.

Coppicing is a growth habit that involves multiple trunks growing out of an underground root.

"The coppicing may be the way this prehistoric tree, suspected of being fire-sensitive, survived the drying out of the Australian continent since the last ice age."

Nevertheless, said Benson, fire has no doubt been partially responsible for the Wollemi's decline. Pollen evidence shows that it was most abundant 50 million years ago when the continent was further south and the climate more moist, and remaining stands of the tree are confined to wet ledges in deep, sheltered rainforest gorges, surrounded by dry country adapted to burns every five to 25 years.

"The species is most likely fire-sensitive but may be able to survive a fire once every 500 to 1000 years."

"If fires get too frequent, they will eliminate the Wollemi," said Benson.

He said that while fires were becoming more frequent in forests near areas of dense human population, it was unclear whether fires were becoming more frequent in the relatively remote Wollemi National Park.

"My gut feeling is they are not because fires there are mainly started by lightning strikes," he said.

One hundred mature adult Wollemi Pines are now known to exist, and while early studies suggested the lowest genetic variability of any plant in the world, recent research has discovered some genetic variation which means it may be slightly more tolerant of changing environmental conditions.

More than 5,000 seedlings of Wollemi have also been cultivated, as part of a project to propagate and commercialise the tree so people can grow them in their backyards without having to trample the wild stands that remain.